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Biomedical subjects

S Tsukamoto

Publications and source records attributed to S Tsukamoto.

At least 127 records · Page 7Linked to original sources
PubMed1989

Determinations of ethanol, acetaldehyde and acetate in blood and urine during alcohol oxidation in man.

Blood and urine samples were analyzed for ethanol, acetaldehyde and acetate during alcohol oxidation in Japanese men by head space gas chromatography, following the consumption of 16 ml/kg of beer during a 20 min period. The maximum level of blood/urine ethanol was found to be 15-17 mM (20-22 mM), while that of acetaldehyde in a flusher and in non-flushers was 20 microM (52 microM) and 2-5 microM (10-13 microM), respectively. Acetate levels in these groups ranged from 0.2 mM (0.1 mM) to 0.8 mM (1.0 mM). Blood ethanol levels were dose dependent, whereas acetaldehyde and acetate levels reflected individual metabolic rates. The relative concentrations of ethanol and acetaldehyde in blood and that of acetate in alcohol metabolism could be summarized as follows: 7500 (15 mM): 1-3 (2-5 microM); 250-400 (0.5-0.8 mM) for non-flushers; and 7500 (15 mM): 5-10 (10-20 microM): 250-400 (0.5-0.8 mM) for a flusher.

Acetaldehyde↗
PubMed1989

[An epidemiological study on dental caries of children in Fuji town. 1. Prevalence of dental caries].

An epidemiological investigation on dental caries was undertaken with 810 children of nursery school, kindergarten, elementary and junior high school age in the town of Fuji, saga prefecture which is a mountain village with less movement of the population. From this investigation the following results were obtained regarding the dental caries prevalence and the status of treatment: 1. As for the dental caries prevalence of deciduous teeth, the dft index was 8.8 at age 3, whereas it was 10.7 at age 5. 2. As for the dental caries prevalence of the permanent teeth, the DMFT value was 7.7 at age 12, whereas it was 9.9 at age 14. 3. As for differences based on set, concerning the deciduous teeth, none was not recognized except for the caries prevalence indices at age 11 for the dft index, at age 6 and 11 for the dfs index, and at age 11 for the ft index. 4. As for differences based on sex, concerning the permanent teeth, none was not recognized except for the caries prevalence indices at age 5 and 9 for the DFT and DFS indices, and at 7 for the FT and F tooth rate. 5. There was a tendency toward as significant increase in dental caries in the deciduous teeth. 6. There was a tendency toward as increase in dental caries in permanent teeth from the commencement of eruption and rapid aggravation approximately from the upper grades of elementary school. 7. In the status of treatment of dental caries in deciduous teeth, the ft index was 4.1 at age 6. 8. In the status of treatment of dental caries in permanent teeth, the FT index was 4.5 at age 14. 9. There was no statistically significant difference among kindergarten and nursery school children except for the dft and dfs indices at age 4.

Adolescent↗
PubMed1989

[Experimental study on myocardial preservation with perfluorochemical].

The effect of perfluorochemical as cardioplegic solution was studied with isolated canine hearts. They were divided into two groups as follows each consisting of ten, and cardioplegia was made every 30 minutes during 3 hours of ischemia. Group I: The solution was oxygenated to PaO2 of 542 +/- 67 mmHg (mean +/- SD). Group II: The solution was deoxygenated to PaO2 of 55 +/- 12 mmHg. Both temperature were 20 degrees C. After 3 hours cardiac arrest, the hearts were fixed to the perfusion unit filled up with the diluted blood. Then hemodynamic and biochemical variables were measured every 30 minutes. There were some significant differences between the groups. Hemodynamic indices especially negative LV max dp/dt were recovered excellently in Group I but not so much in Group II. Negative LV max dp/dt, which was the distinction of the diastole, showed significant difference more than positive LV max dp/dt, which was the distinction of the systole. It was considered that under the same condition, negative LV max dp/dt reflected not only compliance but also preparatory ability of the left ventricle, and it could be one of the important indices evaluating cardiac function. As regarding metabolism, delivery of oxygen with cardioplegic solution was good for the aerobic metabolism also after reperfusion, and in these circumstances, catecholamine was available effectively to the hearts. The conclusion is as follows. It is important for myocardial preservation to suppress the anaerobic metabolism and to keep the circumstances in which catecholamine was available effectively. And oxygenated PFC is good to preserve myocardium and useful as cardioplegic solution.

Animals↗
PubMed1987

Studies on the interaction between polyion and counterions by sound velocity (II).

Sound velocities in polyacrylate solutions neutralized by tetraalkylammonium hydroxide were measured at various concentrations of added NACl. From the results, the degree of counterion binding to polyion and the extent of the changes in hydration volume due to ion binding were determined as a function of the degree of neutralization, alpha. The ion binding accompanying the volume changes appeared above about alpha = 0.6 and the ion binding process depended on the charge density of the polyion. The effect of the size of the tetraalkylammonium ion on ion binding was negligibly small.

Journal Article↗
PubMed1986

Survival effect of coenzyme Q10 and naloxone on experimental stroke gerbils.

Coenzyme Q10 (CoQ10) and the opiate antagonist naloxone were compared as to their effect on the survival of mongolian gerbils with unilateral carotid ligation-induced stroke. Without medication all of the stroke gerbils died within 28 hours, but with a subcutaneous implantation of a 10 mg pellet of naloxone, 20% of the gerbils lived for 4 weeks. When a 250 mg pellet of CoQ10 was implanted subcutaneously, a definite effect on survival was observed, with 45% of the stroke gerbils living for 4 weeks. Considering that the action mechanisms of CoQ10 and naloxone are different, the combined use of these drugs in the treatment of stroke needs to be investigated.

Animals↗
PubMed1986

[Combination of radiotherapy with cisplatin in esophageal cancer].

Combination of radiotherapy with Cisplatin was performed in order to improve the results obtained with radiotherapy alone in the treatment of esophageal cancer. The therapeutic effect of this regimen and administration of Cisplatin were analyzed in 7 primary and 8 recurrent esophageal cancer patients from April 1983 to February 1985 in N.I.R.S. Cisplatin 10 mg/m2, without hydration and diuresis, was given daily followed by radiotherapy of 2 Gy daily for five consecutive days. The course was performed for two consecutive weeks and repeated after a one-week withdrawal of Cisplatin alone. Total doses of Cisplatin were 200 mg and the total dosage of radiotherapy including fast neutrons was TDF 110 to 120. Cisplatin 30 to 50 mg/m2 was continued monthly for maintenance every four weeks after the second course. Response rates in primary and recurrent cases were 71.4% and 62.5% respectively. Administration of Cisplatin 10 mg/m2 daily was useful since nausea and vomiting rarely appeared and bone marrow toxicity and renal dysfunction as side effects were mild and reversible. In the combination of radiotherapy with Cisplatin, it seemed most effective to perform radiotherapy immediately after Cisplatin administration, considering the change in serum concentration.

Aged↗
PubMed1985

Study on the metabolism of volatile hydrocarbons in mice--propane, n-butane, and iso-butane.

A study was conducted to establish whether volatile hydrocarbons, such as propane, n-butane and iso-butane, are metabolized in mice or not. In mice having inhaled these gases, isopropanol and acetone were yielded from propane, sec-butanol and methyl ethyl ketone from n-butane, and tert-butanol from iso-butane as the respective metabolites. In addition, liver microsomes were found to contain the enzymic system participating in these metabolisms. In vitro reactions with liver microsomes produced isopropanol from propane, sec-butanol from n-butane, and tert-butanol from iso-butane. It was assumed that hydrocarbons were first converted to (omega-1)-alcohols by microsomal enzyme system and then to corresponding ketones by alcohol dehydrogenase.

Alcohol Oxidoreductases↗
PubMed1985

Effects of bencyclane on concussion following head injury in mice.

Bencyclane showed a dose-dependent anti-concussive effect with a duration of at least 60 minutes in an experimental model of concussion induced by head injury. This long-lasting effect cannot be explained only by the changes in the serum level of the agent or the increase in brain circulation due to its vasodilative action, both of which are of much shorter durations. Our findings suggest that bencyclane causes alterations in brain metabolism, which is partly responsible for reduction in the duration of the experimental concussion.

Animals↗
PubMed1985

Deranged Ca, Al and Mg content in the tissues of patients with chronic renal failure, as measured by non-destructive neutron activation analysis.

Ca, Al and Mg content in the bone, aorta, skin and hair of 55 persons was measured by non-destructive neutron activation analysis. The Ca content in the bone of nondialyzed and dialyzed patients was found to decrease. Al and Mg were relatively higher than Ca in the patients compared to the controls. The present study suggests that fluctuation in the content of Al and Mg may have some relation to renal osteodystrophy such as osteomalacia as well as similar and related disorders. Al and Mg content in the aorta, and that of Ca in the hair of uremic patients, were higher than the controls. The mean Ca content in the skin of the patients was 25% higher than the controls. These findings indicate 1) that Al and Mg are possibly related to the advance of osteodystrophy, and 2) that Ca, Al and Mg deposits in the organs of uremic patients are a reflection of metabolic disorders in chronic renal failure.

Adolescent↗
PubMed1984

Relationships of structure to binding of gamma-aminobutyric acid (GABA) and related compounds with the GABA and benzodiazepine receptors.

The relationship of the structure of gamma-aminobutyric acid (GABA) and 45 related compounds to their binding with the GABA and benzodiazepine (BDZ) receptors was investigated. In the course of evaluating the cross-reactivity of the 45 GABA-related compounds in a GABA radioreceptor assay (GABA-RRA) using [3H]GABA and rat brain synaptic membranes, it became clear that for the molecule to react with GABA-receptors the amino group must be free, but that the carboxy group is not essential. It was also demonstrated that the molecule lost its cross-reactivity if the distance between the alpha-carbon and the amino group exceeded a certain limit, and, additionally, that the cross-reacting potency depended on the stereospecificity of the compound. When the cross-reactivity of GABA related compounds with the GABA receptor was compared with their enhancement of BDZ receptor affinity, a parallelism was found between the two actions. Between d-gamma-amino-beta-hydroxybutyric acid (d-GABOB) and 1-GABOB, however, no difference was found in the BDZ receptor affinity-enhancing effect, although there was a large difference in the cross-reactivity in the GABA-RRA. This indicates that the stereospecificity of the beta-carbon is crucial for the binding of the molecule to the GABA receptor but not essential for its binding to the BDZ receptor, suggesting that the GABA receptor and the BDZ receptor each recognize a different site of the molecule.

Animals↗